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41.
42.
The hydrogen-bonding structure of water-ethanol in whiskey was examined on the basis of (1)H NMR chemical shifts of the OH of water and ethanol. Phenolic acids and aldehydes (gallic, vanillic, and syringic acids; vanillin and syringaldehyde) exhibited their structure-making effects regardless of the presence or absence of 0.1 or 0.2 mol dm(-3) acetic acid. The OH-proton chemical shifts were measured for 32 malt whiskey samples of a distillery, aged for 0-23 years in five different types of casks. The OH-proton chemical shift values of the whiskies shifted toward the lower field in proportion to their contents of total phenols. It can be concluded that the strength of the hydrogen bonding in aged whiskies is directly predominated by acidic and phenolic components gained in oak wood casks and not dependent on just the aging time. 相似文献
43.
Yamazaki S Numano R Abe M Hida A Takahashi R Ueda M Block GD Sakaki Y Menaker M Tei H 《Science (New York, N.Y.)》2000,288(5466):682-685
In multicellular organisms, circadian oscillators are organized into multitissue systems which function as biological clocks that regulate the activities of the organism in relation to environmental cycles and provide an internal temporal framework. To investigate the organization of a mammalian circadian system, we constructed a transgenic rat line in which luciferase is rhythmically expressed under the control of the mouse Per1 promoter. Light emission from cultured suprachiasmatic nuclei (SCN) of these rats was invariably and robustly rhythmic and persisted for up to 32 days in vitro. Liver, lung, and skeletal muscle also expressed circadian rhythms, which damped after two to seven cycles in vitro. In response to advances and delays of the environmental light cycle, the circadian rhythm of light emission from the SCN shifted more rapidly than did the rhythm of locomotor behavior or the rhythms in peripheral tissues. We hypothesize that a self-sustained circadian pacemaker in the SCN entrains circadian oscillators in the periphery to maintain adaptive phase control, which is temporarily lost following large, abrupt shifts in the environmental light cycle. 相似文献
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45.
Nakagawa T Kitagawa H Yasuda Y Tarasov PE Nishida K Gotanda K Sawai Y;Yangtze River Civilization Program Members 《Science (New York, N.Y.)》2003,299(5607):688-691
Pollen records from the annually laminated sediment sequence in Lake Suigetsu, Japan, suggest a sequence of climate changes during the Last Termination that resembles that of the North Atlantic region but with noticeable differences in timing. An interstadial interval commenced a few centuries earlier [approximately 15,000 years before the present (yr B.P.)] than the North Atlantic GI-1 (B?lling) event. Conversely, the onset of a Younger Dryas (YD)-like cold reversal (12,300 to 11,250 yr B.P.) postdated the North Atlantic GS-1 (YD) event by a few centuries. Climate in the Far East during the Last Termination reflected solar insolation changes as much as Atlantic influences. 相似文献
46.
Nestlings of some brood parasitic birds evict hosts' eggs and young soon after hatching, thereby avoiding discrimination by hosts while monopolizing parental care. Eviction carries a cost, however, because lone parasitic nestlings attract a reduced provisioning rate. Here we describe a form of visual signaling used by the evicting Horsfield's hawk-cuckoo (Cuculus fugax) to obtain sufficient food. The chick displays a gape-colored patch on the wing to the host parents as they deliver food, simulating the gaping display of more than one nestling. 相似文献
47.
Matsubara H Yoshimoto S Saito H Jianglin Y Tanaka Y Noda S 《Science (New York, N.Y.)》2008,319(5862):445-447
Shorter-wavelength surface-emitting laser sources are important for a variety of fields, including photonics, information processing, and biology. We report on the creation of a current-driven blue-violet photonic-crystal surface-emitting laser. We have developed a fabrication method, named "air holes retained over growth," in order to construct a two-dimensional gallium nitride (GaN)/air photonic-crystal structure. The resulting periodic structure has a photonic-crystal band-edge effect sufficient for the successful operation of a current-injection surface-emitting laser. This represents an important step in the development of laser sources that could be focused to a size much less than the wavelength and be integrated two-dimensionally at such short wavelengths. 相似文献
48.
Rina KIHARA Yoshinori KASASHIMA Katsuhiko ARAI Yasunori MIYAMOTO 《Journal of Equine Science》2011,22(3):57-60
Injury initiates a repair process characterized by influx of fibroblasts and the rapid
formation of fibrous scar tissue and subsequent tissue contraction. The response to injury
and behavior of the different tendon fibroblast populations, however, has been poorly
characterized. We hypothesized that the fibroblasts recovered from tendon with acute
injury would exhibit different cell properties relating to adhesion, migration and
tensegrity. To test this hypothesis we evaluated the ability of fibroblasts recovered from
normal and injured equine superficial digital flexor tendons (SDFTs). The injured
tendon-derived cells showed greater contraction of the collagen gel but poorer adhesion to
pepsin-digested collagen, and migration over extracellular matrix proteins compared to
normal SDFT-derived fibroblasts. Thus, the cells present within the tendon after injury
display different behavior related to wound healing. 相似文献
49.
Antiallergic tea catechin, (-)-epigallocatechin-3-O-(3-O-methyl)-gallate,suppresses FcepsilonRI expression in human basophilic KU812 cells 总被引:3,自引:0,他引:3
Fujimura Y Tachibana H Maeda-Yamamoto M Miyase T Sano M Yamada K 《Journal of agricultural and food chemistry》2002,50(20):5729-5734
We previously found that the O-methylated derivative of (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG' '3Me), has potent antiallergic activity. The high-affinity IgE receptor, FcepsilonRI, is found at high levels on basophils and mast cells and plays a key role in a series of acute and chronic human allergic reactions. To understand the mechanism of action for the antiallergic EGCG' '3Me, the effect of EGCG' '3Me on the cell surface expression of FcepsilonRI in human basophilic KU812 cells was examined. Flow cytometric analysis showed that EGCG' '3Me was able to decrease the cell surface expression of FcepsilonRI. Moreover, immunoblot analysis revealed that total cellular expression of the FcepsilonRI alpha chain decreased upon treatment with EGCG' '3Me. FcepsilonRI is a tetrameric structure comprising one alpha chain, one beta chain, and two gamma chains. The level of mRNA production of each subunit in KU812 cells was investigated. EGCG' '3Me reduced FcepsilonRI alpha and gamma mRNA levels. The cross-linkage of FcepsilonRI causes the activation of basophils, which leads to the secretion of inflammatory mediators including histamine. EGCG' '3Me treatment inhibited the FcepsilonRI cross-linking-induced histamine release. These results suggested that EGCG' '3Me can negatively regulate basophil activation through the suppression of FcepsilonRI expression. 相似文献
50.
Preimplantation development of embryos in labrador retrievers 总被引:1,自引:0,他引:1
Abe Y Suwa Y Yanagimoto-Ueta Y Suzuki H 《The Journal of reproduction and development》2008,54(2):135-137
Preimplantation development of canine embryos is not well understood. To understand the timing of preattachment embryogenesis relative to the luteinizing hormone (LH) surge, early embryonic development was examined in Labrador Retrievers after artificial insemination. The embryos migrated from the oviduct to the uterus beginning on day 11 after the LH surge. This transport must be completed within 24 h. By day 13 after the LH surge, all of the embryos had moved and were localized in the uterus. The embryos developed to the morula stage within 11-13 days and to the blastocyst stage within 14 days after the LH surge, respectively. These findings add to the current understanding concerning the physiology of preimplantation development and should help further develop assisted reproductive techniques in canine species, such as cryopreservation and subsequent embryo transfer. 相似文献